1. Field of the Invention
The present invention is in the field of pressurized pulse dampener devices of the type frequently employed in hydraulic systems to minimize the transmission of pulses generated, for instance, in a hydraulic pump, to the hydraulic system downstream of the dampener.
2. The Prior Art
It is conventional in accordance with current practice to employ in a hydraulic system wherein pulses are created, such as by a multiple piston pump, a pulse dampener the function of which is to reduce the deleterious effects of pulses within the system. By way of example, pulse dampeners of the type described are illustrated in U.S. Pat. Nos. 3,782,418, 3,857,413 and 4,069,844. Such devices typically comprise a pressure vessel divided into two chambers by a movable boundary, such as an elastomeric bladder. One chamber is charged with a gas under pressure and the other chamber is communicated, via an oil port, with the liquid in the hydraulic system.
When the pressure in the gas chamber exceeds pressures in the hydraulic system, the bladder or a valve actuated by the bladder is caused to seal the oil port. When the pressure within the hydraulic line, either by way of a pulse or by way of a steady pressure, exceeds the pressure in the gas chamber, the valve member is unseated from the oil port and hydraulic liquid is caused to flow into the oil chamber to compress the gas therein.
The energy resulting from compression of the gas in the chamber is absorbed in the gaseous medium and when the pressure in the hydraulic line falls below that in the gas chamber, is retransferred by the expanding gases back to the hydraulic fluid, whereby the pressures in the hydraulic system downstream of the accumulator are rendered far more constant than the pressure upstream.
In the absence of a dampener device, the pulses generated may be sufficiently severe to cause damage to other components in the system, rupture pipes, and the like, the problem being compounded by harmonic effects in the system which may magnify the deleterious effects of the generated pulses.
Since frequency and amplitude of pulses generated in each environment will vary from installation to installation, and since variations in the fluids processed, pumps employed and like factors, will, in large measure, present different dampening requirements in each instance, it has heretofore been necessary to provide a relatively wide range of dampener assemblies having different dampening characteristics and, in many instances, experimentally to employ a number of such devices on a trial and error basis in a specific installation to effect efficient dampening.
Further, in a given installation where one or more of the variable factors is changed, i.e. where a different pump is used or the pump speed is modified, a substitute dampening device may be required.